Means for longitudinally slitting webs of paper or other flexible material



Dec. 18, 1956 v. HORNSTEIN EIAL 2,774,425

MEANS FOR LONGITUDINALLY SLITTING WEBS OF Filed Dec. 18, 1953 PAPER OROTHER FLEXIBLE MATERIAL 2 Sheets-Sheet 1 21220 1212160115 1 HzDZmz/jaKi? 1L 5 Dec. 18, 1956 v. HORNSTEIN ETAL 5 MEANS FOR LONGITUDINAL-LYSLITTING WEB-S OF PAPER OR OTHER FLEXIBLE MATERIAL Filed Dec. 18, 1953 2Sheets-Sheet 2 Fig. M

lav e ia s l/T iopmiem United States Patent MEANS FQR LGNGITUDINALLYSLITTING WEBS OF PAPER OR OTHER FLEXIBLE MATERIAL Victor Hornstein,Dusseldorf-Lohausen, and Karl Schelp, Dnsseldorf-Wersten, Germany,assignors of one-half to Jagenberg-Werke Akt.-Ges., Dusseldorf, GermanyApplication December 18, 1953, Serial No. 399,138

15 Claims. (Cl. 164-60) The present invention broadly relates to the artof slitting webs of flexible material.

Specifically this invention relates to means for longitudinally slittingwebs of paper or other flexible material.

Still more specifically this invention relates to means forlongitudinally slitting running webs of paper or other flexible materialin which the Web to be slit is guided between a smooth counter-cylinderor counter-roll and one or more disk knives that cooperate with thecountercylinder.

This form of slitting in practice termed notch-slitting is limited inits possibilities of use and is generally more or less restricted to usewith materials susceptible to being slit in this fashion and withrespect to which too high pretensions are not made as regards a smoothand carefully produced slit edge. However, notch-slitting has certainadvantages compared to the more commonly used slitting means whichconsist of circular knives and counter-disk knives in that thecounter-disk knives that normally cooperate with circular disk knives inthe prior art are replaced by a single smooth roll or thecountercylinder; additionally, notch-slitting permits the possibility ofsirnple adjustment for different widths of slits or strips obtained froma web by a simple axial displacement of the disk knives that cooperatewith the smooth counter-cylinder.

In order to provide for completely slitting a running web of material,circular knoves in a notch-slitting operation, that is the slittingmeans that cooperate with a smooth counter-cylinder, rest on thecounter-cylinder with a determined pressure. For this reason suchslitting means are not provided with very sharp slitting edges so as toprevent the spoilation or wear of the cutting edge and the formation ofscores or grooves on the smooth counter-cylinder. To the contrary, thecutting edges of knives used in notch-slitting have a slightly roundededge which will efiect the inconvenience of a rough incision.Furthermore, in instances where a diskknife having a very sharp cuttingedge cooperates with a smooth counter-cylinder under positioningpressure determined by a threaded spindle or other suitable cuttingmeans, the sharp cutting edge is exposed to rapid wear and tear due tothe vibration of the smooth countercylinder during the course of theoperation of the slitting machine, since the disk knives due to beingrigidly fastened down do not yield or participate in the vibrations ofthe counter-cylinder independently thereof.

Therefore, the present invention has for an object to provide means forlongitudinally slitting running webs of paper or other flexible materialpermitting the use of a disk knife or knives having sharp cutting edgesand whi h knife or knives cooperate with a smooth countercylinder.

As a specific object, the invention provide sia mounting for theslitting means which permits the knife or knives to follow thevibrations of the smooth counter-cylinder so that the knife or knivesare not damaged and premature wear and tear thereof is avoided. e

2,774,425 Pate ted D .8 .955

One means of accomplishing the aforegoing object provides a structuraldisposition in which the disk knife means resting upon or riding on thesmooth countercylinder cooperates with a second disk knife means alsoapplied against the counter-cylinder. The structure is such that theintermediate space between the disk knife means, which are opposed toone another, corresponds to the diameter of the counter-cylinder, andthis space is maintained invariable by mounting both knife means on alever means rockably mounted about a fixed center of rotation. Due tothis arrangement, the smooth counter-cylinder is contacted from oppositepoints in a snap-gauge-like fashion with the effect that one of theknife means serves as a distance sustainer to the other. In the instancewhere the machine is running with no load, that is if the dead weight ofthe disk knives is balanced for example by counter-poise orcounter-cylinder, the pressure between the disk knives and the counter.-cylinder will be practically equal to zero, whereas the so-called chippressure caused by the slitting operation will not be greater than thepressure necessary for effectively intersecting the web or webs ofmaterial.

This supporting arrangement which maintains an invariable distancebetween the cooperating disk knife means supported on a lever that isfreely movable around a stationary pivot, permits the knives to followthe vibrations emanating in the smooth counter-cylinder, thuseliminating damage to the knives and premature wear and tear due to anysuddenly increasing bearing pressure between the knife means and thecounter-cylinder.

The second disk-knife means cooperating with the first disk-knife meansmay, in a modification, be replaced by a smooth roll. This is ininstances where the machine is slitting thin or preferably uniformlythick webs of material. The smooth roll lies upon the surface of the webthat is guided around the counter-cylinder. Thus in this case, thedisk-knife means and the guide roll cooperate in the same manner as thetwo disk-knife means previously mentioned. However, the guide rollfunction'- ing as a distance sustainer for the disk-knife means bears orrolls 01f on the paper or flexible web being slit rather than beingdisposed in direct contact with the countercylinder. In the firstinstance, the second disk-knife means runs in the same cutting path asthe first diskknife means. Specifically where disk-knife means aremounted one above the other in relation to a horizontal counter-roll orcylinder they would be in the same vertical plane, although this is notto be considered a limitation.

If the web to he out has an irregular thickness, due to overlappings orthe like and a guide roll was utilized which would have to adapt itselfto the bearing pressure of a disk knife rigidly connected therewith,then the bearing pressure would be increased and the danger of prematurewear and tear of the cutting tools or knives and a constant scoring ordeterioration of the counter cylinder would be present. Thus in order toeliminate this disadvantage, the invention has for a further object andas a specifically modified form, to provide a mounting including adisk-knife means and a smooth guide roll that cooperates therewith butwhich is capable of yielding in accordance with variations of thicknessarising in the web being slit.

In this form, the mounting for the disk-knife means and guide rollincludes two independent levers, one carrying the disk knife and theother the guide roll. Both levers are mounted for movement around acommon center but are limited as to the minimum distance that can existbetween the ends thereof carrying the knife an r es st lwb an d u b s pw eps Wi this r me t t e he rin Pressu e 9. I th d sk a periphery of theknives 3 and 4;

knife thatiis required to slit the ,web is sustained to be substantiallyconstant as regards its effect on the smooth counter-cylinder. The two'lever means are urged toward one another by 'Spring means. Therefore themounting has the elfect of a rigid connection between the disk knife andguide tell if. the web is of uniform thickness. Howe'ver, when there isa variation in the thickness of the web, the spring normally maintainingthe guide roll and disk knife' at an invariable distance, will permitthe yielding of the guide roll to accommodate the variation inthickness. 7 Further and more specific objects will be apparent from theaccompanying drawings schematically illustrating two embodiments of theinvention and in which: Figure 1 illustrates an arrangement in which asecond disk-knife means functioning as a distance sustainer, co-

operates with the first disk-knife means.

Figure 1a is a front view of Figure 1.

Figure 2 illustrates an arrangement in which a guide roll cooperateswith the first disk-knife means.

Figure 2a is a front view of the arrangement shown in Figure 1.

In the arrangement illustrated, the web 1 to be slit is fedotf of asupply reel, not shown, and guided around a smooth counter-cylinder 2and then rewound by a suitable rewinding means, not shown.

the web around the counter-cylinder, the same will be slit into one ormore strips by means or one or more disk knives 3 that bear against theopposite portions of the counter-cylinder 2. The disk knife 3 isoperatively' coupled with a second disk knife 4 50 that the two knivesor sets of knives where plural knives are embodied, lie facing oneanother and contact the periphery of the counter-cylinder 2 with thediameter of the countercylinder being equivalent to the spacing betweenthe The knife means 3 and 4 are supported in a rotatable manner bypintle or axle means 3' 4' at the free ends of lever 5. This is atwo-arm lever and substantially U-shaped in plan with the knife meansbeing mounted in the free ends of the legs of the U. The lever 5 ispivotally mounted about a fixed center of rotation or pivot v6. Sincethe lever is rigid, a constant distance between'the disk knives 3 and 4and the counter-cylinder 2 is assured by means of the invariable angleof motion limitedby the center of rotation 6 and the centers of the diskknives 3 and 4. Thus as is shown, the axis of the center of rotationfilies in the same plane as the axis of the counter-cylinder and therespective legs of the lever 5 are at equal distance from the plane bi+secting' the center 6 and the counter-cylinder 2.

In the form shown in Figures 1 and la, the two knives 3 and 4 lie in acommon slitting plane, that is the disk knife 4 runs in the slit thathas been produced by the disk knife 3. However, the invention issusceptible to utilization. in instances where the disk knives lie indifferent slitting planes and disk knife 4 has a slitting functionindependent-of the slitting effected by the disk knife 3. Suchembodiment, as shown in Figure 3 would include a mounting in which onedisk knife 3 is offset from the other knife 4 in the directionlongitudinally of the counter-cylinder 2.

In order to fully compensate for the dead weight of During passage of isnot of uniform thickness. In this arrangement, the disk knife 3" isfreely rotatably mounted in the end of a lever 5' rockably mounted aboutthe stationary pivot 6.

Also rockably mounted about this same stationary center or pivot is afurther lever 5", which'at its free end journals a smooth guide roll 4'The distance between the circumference of the disk knife 3 and thecircumference of the guide roll 4" corresponds substantially to thediameter of the counter-cylinder 2. The lever 5"carries a stop 8 in aposition adjacent to center of rotation 6 and which stop extends towardthe counter-cylinder. A set-screw means 9 is carried by the lever 5' forcooperation with the stop 8. The contact between the set-screw and stopor abutment 8 determines the minimum 'distance between the periphery ofknife 3" and roll 4" and a traction spring 10'connects the twoleve1's'5', 5" together. This arrangement permits effective operation ofthe Web 1 in a manner with 'only slight bearing pressure existingbetween the knife 3 and the counter-cylinder 2,

and in which any vibrations emanating'in the counter-- cylinder 2 willnot cause a detrimental increase of the bearing pressure sincethe'slitting means'as a whole constituted by the disk knife 3" and theguide roll 4'. re: main constant when websof normal thickness oruniformity in thickness are being slit since the levers 5, 5"

jointly took about pivot 6'. However, in instances where V the web is ofnon-uniform thickness or an unevenness in the web is involved, the guideroll 4" will yield without increasing the bearing pressure to such anextent that the cutting edge of the knife will be damaged. lTheinvention also contemplates an arrangement in which a guide roll issubstituted for the knife 4 in the 7 form of Figure l. v

What is claimed is:

-l. Means for slitting a web of paper or other flexible materiallongitudinally thereofcomprising a smooth counter-cylinder around whicha web to be slit passes, diskknife means movably mounted with respect tothe axis of the counter-cylinder and cooperating with one portion of thecounter-cylinder for slitting the web, said disk-knife means having anaxis parallel to the cylinder axis, ad

ditional means freely rotatable about an axis parallel to theaforementioned axes and cooperating with an opposite portion of thecountencylinder and means operably coupling the said additional means tothe diskknife means so as to constitute a distance sustainer for thedisk-knife means.

2. Means as'defined in and by claim 1 in which the additional meansconstitutesa second disk-knife means.

3. Means as defined in and by claim 1 in which the additional meansconstitutes a guide roll.

' 4. 'Means as defined in'and by claim 1 in which the additional meansconstitutes a second disk-knife means and in which the first and seconddisk-knife means lie in a common slitting plane.

5. Means as defined in and by claim 1 in which the additional meansconstitutes a second disk-knife means and in which the first and seconddisk-knife means lie in different'slitting planes. 7

6." In a web slitting mechanism a smooth counter-cylinde'r-around whicha flexible web to be slit passes, a slitting means cooperable therewithto slit the web longi- 7 tudinally comprising a rotatable disk-knife,means and a further rotatable means, said disk-knife means and furthedisk knives 3 and 4 and of the lever 5, a counterweight of the leverarms and the means and the cylinder and between the further rotatableabout an axis parallel to the axis of the cylinder but on 'In Figures 2and 2a, there is disclosed an arrangement that is' especially suitablefor use when the web to be'slit' ther rotatable means being disposed onopposite sides of and cooperating with the counter-cylinder at areasthereof lying on opposite sides of a plane bisecting the cylinder sothat the web passes between'the disk-knife means and the cylinder in itspassage around the cylinder, lever means carrying the disk-knife meansand the further freely rotatable means at a minimum distance apart andfixed pivot means supporting the lever means the side thereofadjacent'the side of the cylinderembraced by the webfin its passage. 1

7. Web slitting mechanism as defined in and by claim 6 in which thelever means is rigid and common to both the disk-knife means and thefurther freely rotatable means and the fixed pivot means has a center ofrotation displaced laterally of the axis of the counter-cylinder butlying in the plane passing through the axis of the cylinder that isnormal to the plane passing through the axes of the knife means and thefurther rotatable means in a direction axially thereof and the angle ofmotion of the lever means formed by the center of rotation of the levermeans and the respective centers of the knife means and the furtherfreely rotatable means being invariable.

8. Web slitting mechanism of the type defined in and by claim 6 in whichthe lever means includes two independently movable arms extending towardthe axis of the counter-cylinder and lying on opposite sides of a planepassing through said axis, one arm carrying the disk-knife means and theother arm carrying the freely rotatable means and means operative tonormally maintain the arms at a minimum distance apart for slitting websof uniform thickness but operable to permit an increase of this distanceupon an increase in the thickness of the web.

9. Web slitting mechanism of the type defined in and by claim 8 in whichthe means normally maintaining the arms at a minimum distance apartinclude mutually engageable stop means carried by each arm.

10. Web slitting mechanism of the type defined in and by claim 9 andresilient means normally urging the arms toward one another.

11. Web slitting mechanism of the type defined in and by claim 10 inwhich the further freely rotatable means is a guide roll.

12. Web slitting mechanism of the type defined in and by claim 11 inwhich the disk-knife means and the guide roll are aligned in a planenormal to the axis of the counter-cylinder.

13. In a web slitting mechanism a smooth countercylinder around which aweb to be slit passes, a fixed pivot means displaced forwardly of thecounter-cylinder with regard to the direction of movement of the webtoward the counter-cylinder, lever means pivotally mounted on said pivotand including spaced interconnected arms extending toward thecounter-cylinder and lying respectively on opposite sides of the axisthereof,

disk-knife means carried by one of the arms and freely rotatable meanscarried by the other arm, said disk-knife means cooperating with thecounter-cylinder to slit the web longitudinally and said freelyrotatable means cooperating with the counter-cylinder through theinterconnected lever arms to control bearing pressure exerted on thecounter-cylinder by the disk knife.

14. Web slitting mechanism of the type defined in and by claim 13 inwhich the two arms are independently pivotally mounted on the pivot,resilient means interconnecting and urging the arms toward one anotherand an abutment means carried by each arm and mutually engageable withone another to limit the movement of the arms toward one another whilepermitting movement of one arm relative to the other in the directionopposite to the minimum distance.

15. In a mechanism for slitting a web of flexible materiallongitudinally thereof a cylinder about which the web to be slit passes,a fixed pivot spaced from the cylinder and lying on the side thereofadjacent that side embraced by the web in its passage around thecylinder, lever arm means supported by the fixed pivot for rotationthereon and including portions extending toward the cylinder but lyingon opposite sides of its axis, a disk-knife means carried by one of saidportions for rotation about an axis parallel to the cylinder axis andcooperable with the cylinder for slitting the web, additional rotatablemeans carried by the other of said portions and cooperable with thecylinder at an area diametrically opposite the area engaged by thedisk-knife means and means operably connected to the lever arm means forcompensating for the dead weight of the lever arm means, the disk-knifemeans and the additional rotatable means.

References Cited in the file of this patent UNITED STATES PATENTS1,765,208 Cunningham June 17, 1930 1,841,251 Miller Jan. 12, 19322,205,564 Johnstone June 25, 1940 2,553,052 Kwitek May 15, 1951 FOREIGNPATENTS 1,070,070 France Feb. 17, 1954 145,814 Sweden Apr. 1, 1954

